1. Field of the Invention
The invention relates to a method and apparatus in the field of culturing and harvesting aquatic organisms, specifically, pumps for displacing aquaculture water, when the organisms are in a confined, protected or controlled environment.
2. Description of Related Art and Information
In the culturing and harvesting of aquatic organisms such as fish, crustaceans, frogs and other aquatic life forms, a high injury and mortality rate can result to the organisms during capturing as the result of using current methods and devices. For example, seining, netting and other capturing methods can cause injury to the organisms and are inefficient techniques. When organisms are seined or netted, they can suffer extensive damage from the crushing weight of remaining fish. Multiple passes of a net can result in further injury, is costly and is all inclusive in harvesting results.
Considerable damage can also occur as fish, lobster, prawns, shrimp and other organisms are sorted from entanglement with the netting. Most injuries to the organisms occur at harvesting or during post-harvest treatment with harvesting being a tedious and time consuming job. Such delays in processing result in a deterioration of organism quality when packed for shipping. Also, many aquaculture products, from fresh water lobster to ornamental fish, must enter the market place alive.
In addition, many species must be sent to processing plants alive to prevent enzyme damage that occurs immediately following death. Frogs are particularly difficult to harvest and grade at anytime pre and post metamorphic, using present methods. The system of the present invention makes frog harvesting safe and easy.
Harvesting and fish-moving techniques, as practiced today, are costly, damaging, self limiting and allow a certain percentage of fish to escape. The art, as practiced, lacks portability, requires a great deal of time to establish in the field, does not protect aquatic organisms from predation and does not produce a controlled environment.
Frequently, fish escape the net at harvest time and then become predators the following year. To prevent this, using today's available methods, lakes, ponds or other aquaculture production units, must be drained, disked, dried and refilled. This adds a great deal of cost to the operation. If wild stocks are left to over-winter, there is a chance of genetic or disease contamination.
In addition, certain species, such as the salmon fish of the Pacific Northwest, have been placed on the endangered species list because of interruption of migratory patterns due to the construction of hydroelectric dams on, for example, the Columbia and Snake Rivers. It is impossible for adult salmon to negotiate these dams in upstream migration. The addition of fish ladders to aid the upstream migration has largely failed. On the other hand, young fry, hatched upstream above the dams, are unable to safely reach their downstream destination with thousands perishing in the effort. This results in an interruption of the salmon's natural reproductive instinct and pattern. The method of the present invention provides a safe, effective and alternative solution to fulfilling the migratory requirements of these fish and will allow these species to flourish once again. It also allows hatched fry to be safely moved downstream beyond obstructing dams.
The method and apparatus of the present invention combines layered membranes that are peripherally sealed resulting in a potential space that can be inflated with air or a fluid. As the space is inflated, it functions as a pump displacing overlying culture water in a culture chamber or other fluids in a controlled amount and direction. Layered membranes are known in the art and are used for many purposes, but none have been constructed, used or anticipated to achieve the results of the present invention. While there are many devices and methods of aquatic culturing, the art does not describe, claim or anticipate culturing, harvesting or moving aquatic organisms using a water displacement and re-cycling device and method of the present invention.
U.S. Pat. No. 5,216,976, to Marinkovich, Method and Apparatus for High-Intensity Controlled Environment Aquaculture, describes and claims a controlled environment in which a metal framework supported dome is placed over a body of water to create an enclosed eco-system by which the water can be heated by a thermal blanket lining the body of water as well as by bubbling heated air through the water. The thermal blanket is covered with a soil substrate. This invention neither claims or anticipates a layered water displacement apparatus or method of the present invention. U.S. Pat. No. 4,160,523, to Stevens, Air Structure, describes and claims a layered and compartmentalized dome that has buoyancy created by solar-heated air. It further describes a use in association with the construction of a greenhouse. It neither describes or anticipates a use integral to an aquatic culture facility in which the ground and greenhouse units are constructed as one unit and designed to maintain temperature, humidity, and water recycling in aquatic culturing and harvesting.
U.S. Pat. No. 3,834,167, to Tabor, Collapsible Dam and Damming Method, describes and claims a inflatable/collapsible envelope that is mounted across a water course for the purpose of creating a damming effect. It is not a water-containing device nor does it describe, claim or anticipate a device or method in the use of culturing or harvesting aquaculture.